فهرست مطالب a. malian

Porous materials especially closed-cell metallic foams play important roles among novel materials because of their good characteristics e.g. high strength to weight ratio and crashworthiness. On the other hand, mechanical behavior determination and detailed characterization are essential in efficient manipulation and material tailoring. In the present research especial hybrid experimental-numerical approach is used for aluminum foam behavior determination as to the main goal, i.e. continuous deformation field measurement using digital image correlation (DIC) and finite element analysis (FEA) on porous specimen’s surface.  To overcome the 3D modelling problem of closed-cell foams structure, we present the method based on CT-scan and digital optic microscope imaging combination. In the experimental part of the study, aluminum foams and proper specimens are manufactured, and then high-resolution digital imaging and illumination setup are employed. Finally, the deformation field is obtained using DIC. On the other hand, measurement verification and DIC parameters optimization processes are conducted using ABAQUS 2019 with comprehensive mesh independency study and response surface methodology (RSM) respectively as major research achievement. Finally, correlation equations based on high regression models are obtained. Using detailed geometrical micro-model and optimal DIC parameters yields to good numerical-experimental accordance. The novel approach of combined CT and digital microscope imaging instead of industrial micro-CT lowered imaging costs while yielded to accurate numerical results.

Providing information layers including the most important means of facilitating land use in urban areas are in the process of crisis management. Urban management based on their knowledge and information layers of the urban side, preclude a broader crisis. Remote sensing technology and fast as science and technology plays an important role in the production of information. Urban effects and a wide detection of satellite images have useful applications in various fields, including automating the process of identifying and extracting data from images and update database information system locations. The purpose of this research is to introduce and implement automated way to extract information congested urban land cover in the region, based on object-based methods and analysis in the context of satellite images with high spatial resolution. After the proposed procedure hierarchical segmentation process, to produce the texture descriptors for each of the events will be discussed. The method proposed in this study was 86% overall accuracy and kappa coefficient 0.83 satellite image was obtained for the detection of complications city.